Justification:
The lake populations have increasing difficulty in reaching the spawning places in the tributaries. Although the introduced subpopulations are thriving, the threat to the remaining severely fragmented natural population and spawning areas is high due to dam construction, pollution, water extraction and predation by cormorants and Silurus glanis. The area of occupancy (AOO) (based on the spawning grounds) is estimated at less than 500 km². It is locally extinct in Slovenia and the Isonzo river basin in Italy due to the introduction of Chondrostoma nasus, a practice still implemented.

Restricted to northern Italy, the southern part of Switzerland. It has been introduced in some Italian lakes. It is locally extinct in Slovenia and the Isonzo river basin in Italy due to the introduction of Chondrostoma nasus, a practice still implemented.Recorded introductions into the rivers of central Italy were often a misidentification for C. genei. Several present records for C. soetta are probably a misidentification for C. nasus, due to similarities between these two species. As an example of how the alien species are spread now in Italy, in rivers from the Rovigo Province in eastern Italy, where C. soetta is still reported, the biomass of all native species was found to be about 22% of whole ichthyofauna.

Very different from one locality to another. It is locally extinct in Slovenia but still thriving in other parts of its range. This species is now becoming quite rare in the lakes of northern Italy and Switzerland (Lugano, Maggiore, Como, Iseo, Garda) mainly as result of interaction with alien species, especially Rutilus rutilus, which was introduced around 1990 and has become very common and is the subject of commercial fishing in several of these lakes. (Bianco, P. pers. comm). This species is also rarely found in rivers and has nearly disappeared in the main stretch of the Po basin, in the other rivers it forms very small populations and spawning occurs only in a few areas of each river (except in the Po).

Dams, water pollution and extraction, and introduction of alien species as Rutilus rutilus, Silurus glanis and Chondrostoma nasus. The reduction in suitable spawning places due to pollution (agriculture) and to water extraction is of major concern.Other threats to the species are predation by cormorants, where in several places of Italy have become a serious pest and destroyed a large amount of fishes, especially in torrents or small river were the fishes migrate to for reproduction. (Compiled by C.esare Puzzi from GRAIA, and P.G. Bianco pers comm.).

Bianco, P.G. and Ketmaier V. 2001. Anthropogenic changes in the freshwater fish fauna in Italy with reference to the central region and Barbus graellsii, a newly established alien species of Iberian origin. Journal of Fish Biology 59: 190–208.